Entosphenus macrostomus (Beamish, 1982)
Vancouver lamprey
Entosphenus macrostomus
photo by Canadian Museum of Nature, Ottawa, Canada

Family:  Petromyzontidae (Northern lampreys), subfamily: Lampetrinae
Max. size:  27.3 cm TL (male/unsexed); max.weight: 19.8 g; max. reported age: 2 years
Environment:  demersal, non-migratory
Distribution:  North America: southern Vancouver Island, British Columbia. Occurrence in USA needs confirmation (Ref. 2583).
Diagnosis:  Adults: 11.8-27.3 cm TL; body wet weigth of a 22.1 cm TL individual, 19.8 g; body proportions, as percentage of TL (based on 112 specimens measuring 11.8-27.3 cm TL): prebranchial length, 14.3-17.6; branchial length, 9.4-12.6; trunk length, 37.5-48.2; tail length, 20.9-31.7; eye length, 2.2-3.5; disc length, 6.5-11.7; trunk myomeres, 59-70. Adult dentition: marginals, 54-67; supraoral lamina, 3, rarely 4 unicuspid teeth, the median one smaller than the lateral ones; infraoral lamina, 5-6 unicuspid teeth; 4 endolaterals on each side; endolateral formula, typically 2-3-3-2; 2 rows of anterials; first row of anterials, 3 unicuspid teeth; exolaterals absent; 1 row of posterials, 14-21 teeth, 2-3 lateralmost on each side bicuspid and the internal ones unicuspid; transverse lingual lamina, 13-20 unicuspid teeth, the median one slightly enlarged; longitudinal lingual laminae parentheses-shaped and each with 17-27 unicuspid teeth. Velar tentacles in adults, 11-15 with wings. Adult body coloration (preserved), uniformly dark, almost black; lateral line neuromasts darkly pigmented; extent of caudal fin pigmentation, 75% or more; caudal fin shape, spade-like; oral fimbriae, 117; oral papillae, 17.
Biology:  Spawns on shallow gravel bars in freshwater lakes or the mouths of creeks flowing into lakes. Ammocoetes larvae occur in silt, mud, or sand in quiet water (Ref. 5723). Ammocoetes are found in inlet streams within 100 m of two lakes in Vancouver Island, British Columbia. Ammocoetes and recently metamorphosed individuals are mostly found along the edges of lakes. Adult life span believed to be at least 2 years. Adults parasitic on fishes (Oncorhynchus clarkia and O. kisutch) in freshwater lakes throughout the year. Wounds produced known to penetrate deeply into the musculature or even reach the body cavity of hosts. Up to three adults have been recorded attached to a host. Adults are known experimentally to be able to survive in salt water, but apparently remain in fresh water despite the absence of barriers preventing access to the sea. Adults in spawning readiness collected from shallow gravel bars between 1 June and 23 August. Between 50 and 80% of fishes, mostly salmonids, in Lake Cowichan and Mesachie Lake show evidence of attacks from this lamprey, and based on the severity of the wounds inflicted, an estimated 15% of these attacks would probably result in the death of the host (Ref. 89241).
IUCN Red List Status: Endangered (EN); Date assessed: 22 July 2015 (B1ab(iii)+2ab(iii)) Ref. (120744)
Threat to humans:  harmless
Country info:   
 

Entered by: Froese, Rainer - 27.01.92
Modified by: Luna, Susan M. - 23.09.16
Checked by: Torres, Armi G. - 19.04.94

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